Verified answer

this is a toughie! It can be solved by graphing and finding the x-intercept of y=x^3+x^2-49. I got:

x ≈ 3.35

that's it! ;)

7/x=√(x+1)

(7/x)²=x+1

(49/x²)=x+1

49=x²(x+1)

-x³-x²+49=0

Go to http://www.wolframalpha.com/ to find out the answer. Just enter the equation.